Permission is granted to link to the schematics on this page however I do not extend permission to place copies of the schematics stored on this site on other sites. In other words, you can link, but don't download and place them on your server and show them as yours.

Before you go wild downloading these links and buying parts for the schematics listed below, there are a few things you should know.

I encourage you to purchase pedals in production. If it's currently in production and you can afford it, buy it.

Selected Stompbox Schematics

Note that not all of these schematics are guaranteed to work. Some may be completely wrong. A good place to ask about effects is Ampage and alt.guitar.effects, a good newsgroup. I have added notes in red to the schematics believed to have errors. Items confirmed by me or others have an OK! in green. This is not meant to discourage you from trying the other schematics out, just that I haven't heard anything about them.

In very general terms, I would say that probably every schematic on Jack Orman's (AMZ) page is fine; Keen's (GEO) page is excellent as well. Most of Justin Philpott's Site is excellent (he has an effects feedback page), the one's that have verified problems have corrections noted so pay attention to the notes.

The schematics are listed by manufacturer or type or designer with the name of the stompbox and the web site that it is located at. I encourage you to look through these great websites and learn more from the excellent articles on them.

About the files:

Most are .gif or .jpg and can be viewed right away. The files with .pdf at the end need Adobe Acrobat Reader. The files with .ps are Postscript files and need a Postscript Viewer. The files with .ps.Z are compressed (I forget the format... tar?) they need to be uncompressed then viewed with the Posctscript viewer. Stuffit Expander should work on these files.


A/B SwitchBoxes




For more mods to this circuit check out the Brit Face. (Plate to Plate)

Aron Nelson - Circuit-Ware - not shareware, but something like it.

Key points about the Lava Rim 2, uses cheap readily available 2N3904 transistors, sounds good and can get creamy - slightly compressed tones with the drive and input pot set low as well as nasty heavier types of distortion. It's also very easy to build and easily adapts to germanium NPN transistors; the trimpots really allow you to dial in a very good tone.
11/29/99 - The Lava Rim 2 is a versatile circuit! You can mix NPN germanium transistors and silicon transistors for a unique sound. The trim pots let you use all types of transistors such as the 2N5088 for more distortion and gain. In addition, the 2nd transistor can use a MOSFET like the 2N7000 or BS170! Just pop in the MOSFET, drain toward V+, source toward ground and adjust the trim pot until you hear good tone! In addition, remove the diodes to really hear the MOSFET. Thanks to Jack Orman for the tip on using a MOSFET for the 2nd transistor!
11/28/99 - to reduce some of the brightness of the pedal, you may want to put a capacitor (.001uF -> .01uF in parallel with the clipping diodes).
11/6/99 - revision 2 - added bounding pot to diodes for more control over diode distortion.
The Hornet did not happen without the contributions of the usual netizens that help us so often. Alfonso Hermida, GFR, Gus Smalley, Jack Orman, R.G. and others. Thank you guys!
From Jack Orman:
Since the supply of 2N388A transistors have been depleted at Parts Express, I thought I'd post a few alternate devices
that they carry that can be used for F-F construction. Any of the below parts should be suitable and are less than $1
each. The last one is spec-ed a little weak but would likely be okay. The first one is a good sub for the 2N388A.
Part No. Type Hfe Price
2N1306 NPN 100 $ .95
2N1308 NPN 150 $ .75
2N1309 PNP 150 $ .75
2N1373 PNP 60 $ .95
The NTE101 is another choice:
11/8/00 Small Bear has a nice PNP version of the Hornet, check it out!
7/11/99 -
Notes: Not much to this circuit; the trimpots allow you to really tune in and adjust the circuit. Please try the 2N388A transistors as they are dirt cheap (18 cents when bought in lots of 5 or more I think). The 2N5088s can be readily found through Mouser. The rest is pretty much Radio Shack or your local store. Convert to PNP transistors by changing the orientation of the lone 47uF electrolytic and reversing the battery polarity. (The battery AND 47uF cap POSITIVE to ground).
Mods: The input cap is critical; for classic fat fuzz tones use 2.2uF to 10uF to larger! (you may consider socketing it - I did) The output cap is less critical; I have found that .1uF is fine for me. The .05uF that I use I have found to be very good because it changes the frequency response of my guitar the least. I have around the same bass as when the unit is bypassed. The trimpots allow you to really tune in the sound. Many shades of distortion will come out as you fool around and turn them. C? is a high end rolloff cap, you can put .001 to .01 to larger values and hear what it does (socket this cap). You can also put the usual 50K pot at the input BEFORE the input cap as described in the Technology of the Fuzz Face - (GEO) Excellent article about the Fuzz Face.
You could also make the 1K resistor off of Q2's collector a 47K, then make the 100K trim a 47K and tap the output off of the junction between the two. This will reduce your output level and make it a lot tamer.
11/26/99 - Built another one and it works fine. I believe the previous circuit I built on 11/10/96 had some type of bad voodoo in it. The schematic works and is fine. I didn't need the bias pot for the 2nd one.
11/20/99 Revision 6 online. More cleaning up and fixed a mistake.
11/11/99 Revision 5a online. Jack cleaned up a few thing. Thanks!
11/10/99 Revision 5 online. Optional bias pot to stop gating effect of CMOS if you have the gating problem when notes are decaying. You turn the pot until the gating is gone, measure the values of the pot from wiper to lugs and then put in fixed resistors. I have to point out that this is an advanced project. I built another one and it seemed pretty hard to build. So many things to keep track off. In addition, I had to put in the bias control - I just put one bias pot and connected a 1Meg resistor from each inverter input to the pot wiper. I ended with a 33K from 9V to the 1M resistors to inverter inputs, then a 56K resistor to ground.
PCB Layout, Press and peel layout (TIF format) Thanks to John Catto!
11/5/99 Revision 4 online. The trim pot values are now listed. I measured them in circuit , with power off.
11/3/99 Thanks to Jack Orman for pointing out errors and mods. The revised schematic (revision 2) is now online.
Here is the pinout of the CD4049 chip. Here's more on the CD4049 from Jack Orman and GFR.
9/6/99 - I just built The Rocket using GEO's PCB. It was easy to create and gives very professional results. A couple of mods as I played it through my Bassman and a 12" speaker:
Try substituting .047uF caps for both .01uF caps right after the buffer in the front. You can't miss them, they are the only .01uF caps on the entire board. In addition, I really mellowed out the pedal by putting a .2uF cap (two .1uF caps in parallel) instead of the .1uF in the tone control. Remember that if you use caps larger than .1uF instead of the .01uF caps, you will have to increase the input cap value. Basically two .01uF caps will give you a midrange heavy tone with some bass cut - nice and slicing. Anything more will start giving you a smoother rounder tone and increase bass response.
A hi-gain pedal for the guys that want to rock!. The Shaka Express represents the top of the line Shaka for hi-gain overdrive/distortion. The mid "bite" control gives your distortion "teeth" and the 3 FET stages make sure every nuance comes out loud and clear. Step on this pedal and take the lead. PCB and Layout available from GEO. Listen to a sample of the Shaka Express from JPEG available for people that are PDF challenged :-)
The goal of the Shaka Braddah line is to make a pedal that can have tremendous boost into an amp while preserving the tone of your equipment. The circuit should go from soft clipping all the way to heavy overdrive. I believe the Shaka Braddah III achieves this goal.
The Shaka Braddah III was designed for you to be able to set the tone control (around 8-9 o'clock) to a neutral setting and get a booster/distortion that can make your guitar sound hotter and more vibrant. In addition, when the drive settings are turned up, it should sound like your amp is being cranked up.
Thanks to John Greene for the idea of using MOSFETs as diodes.
Note that the parts placement .pdf file incorrectly lists a TL074 for the TL072 IC and a 0.047 instead of .004 capacitor.
Mods to try: 3 or more 1N34a diodes in series on each side of the clipping section. Each diode that you add will raise the clipping threshold and basically allow the Minibooster circuit to distort more before the clipping diodes start adding their sound. What this means is that you will hear more of the FETs before the diodes kick in. In a similar vein, I suppose that you could try 1N914 and 1N4148 diodes for their harsher sound and put then into the circuit. Since I socketed my clipping section, this will be easy for me to try soon. I have tried different ICs (RC4558 and LF353) and although the LF353 sounded different, I still like the sound of the TL072 fine. Try adding the "softness" or clipping threshold control noted in my Simple Mods page.
8/20/00 - Revised drawing. Fixed tone control, removed 100K trim etc....
12/9/99 - Please try different op amps in the Shaka 3 circuit. They make a rather large difference and one that you can fool around with is the TS272CN (part number 511-TS272CN from Mouser). At 72 cents it's a cheap, fun mod. It radically changes the sound of the pedal. The pedal becomes more midrange, distortion is radically different. More sustain at the expense of fidelity. Very interesting.
12/5/99 - If you like highs like I do, remove the 100K trimmer before the Minibooster and change the 10K trimmer on the source of the Minibooster to a 4.7K - that's enough of a trimmer to reduce gain on the Minibooster circuit. The 100K trimmer loads down the circuit and reduces highs a bit.
8/21/99 - There was an omission in the original schematic - my original Shaka III's MiniBooster is also a treble booster. The new schematic reflects this change. With this simple change (1 cap), your Shaka III will be clearer, brighter and punchier. On R.G.'s board (which all of you should purchase), here is the capacitor you should change.
7/4/99 - current consumption is ~5 mA, not bad.
5/18/99 - Try different tone circuits with the Shaka III. Splice different types of tone circuits after the MiniBooster. Try the RAT tone control and others. I think you will find that the Shaka III circuit is extremely versatile and adapts to different tone controls. The pedal sounds very different when used with different tone circuits.
5/9/99 - Notice that my Shaka III doesn't have the 22K resistor going to ground in the tone control section. This probably explains why my pedal doesn't get the scooped mids if this 22K resistor is there.
4/18/99 - Wired 2 IRF520s as MOSFET diodes with a 1N34a diode attached to the source pin. This arrangement sounds extremely natural to me. Wire 2 of these and reverse them in polarity when attaching them to a circuit just like a diode pair.
Diode is 1N34A, MOSFET is IRF510 or IRF520. Make 2 of these and then use them as diodes in the Shaka III.
4/15/99 - Added a trimpot on the schematic which essentially allows you to control the amount of "clean boost" when the drive is turned all the way down. This trimpot allows you to make your "clean boost" really clean or kinda dirty - you know?
4/11/99 - Tried 4 1N34a diodes on each side for a total of 8 diodes! The diode array tested at ~.822. Very nice... Even more nice dynamics, yet still has a smooth sound. I'm going to try some 1N914 and 1N4148 combinations for asymmetrical and other varieties of distortion. I realized I am able to mount the diodes onto sockets essentially creating a clipping "module". I can plug these modules in anytime for different sounds.
Check out Doug Hammond's Shaka Braddah III mods which he calls the Shaka Braddah IV. I did like the sound of his mods. I find that the Rat circuit seems to produce less highs and this may work for amps which are bright.





Blackbox DIY


Boss I would purchase all Boss pedals because most of them are very complicated and they are reasonably priced.


Colorsound (Sola Sound)

WaitAMinute! Look at the Big Muff schematic... Now look at the Jumbo Tone Bender... anything familiar?
Notes from John Catto:
Today a friend of mine gave me a (not working - broken footswitch/one pot) Sola Sound Tone Bender. This is the three knob version built by many people on this board, including myself. There have always been some doubts about the schematic and now was my opportunity to clear this up once and for all!
The schematics posted by RG are pretty close, the only differences are..
1. ALL pots are 100k not 250k and no 2Mg (it appears the Yardbox is a closer clone than thought)
2. The resister from Q2 to earth is 3.3K not 33k
3. The capacitor that parallels the 3.3k resistor is 10uf on my unit not 22uf
4. On my unit there is a 220k resistor between the centre lug of the tone pot and the volume.
The Transistors are all unmarked metal can, no doubt Germanium. The can has a narrow ridge around it about a sixth of the way up.
One more thing, I've always believed that this design is the original design predating the more fuzzface like models with 2 knobs. This one however is dated inside 21 March 1974, so perhaps it is a later design after all or at least was still made that late. The case is a very slightly shallower version of the colorsound box, with silver paint and orange/black text.
Well there it is. I never thought I'd see one of these in the "flesh"
PCB Layout and more on Guitars, Amps and Effects. OK!
Tone Bender Professional Mark II.
Check out the various Bender variations.
Mark Poley contributed his version with tone control! Check it out!


Craig Anderton

Dale VanZile


Dan Armstrong

Note: Jack Orman points out "the resistor from the inverting input to the 47uF cap is way too big: it should be 2k4 or even 240 ohms."

Doug Hammond

This contribution from Doug Hammond is an extension of the ShakaBraddah III which refines various points of the original design. Doug has worked a while on this design and it promises to be very good. All the good attributes of the Shaka Braddah III have been retained with improvements.Here is the PCB.
Some like it HOT and this pedal is built for sizzling leads. Another contribution from Doug Hammond. A Shaka with attitude+! PCB.


Ed Guidry


EQ Circuits


Blum is asking for help on this:
The biggest problems for me are :
- MN 3007, 4047,4066 and 4013 pins
- LM 311 out (I suppose it`s LM 311?) If you have ideas, please post on the forum.
Possible mods and notes: You can try NTE123AP, which is pretty much 2N2222 transistors. Try lower hFE transistors - like 150-250 instead of the usual 400+. Ed Rembold suggests Q1 base to ground 47K.
Simple Deluxe Memory Man reissue mods that can be done. OK!
Notes: According to Jack Orman, "Pin 2 is marked as the non-inverting input when it is actually the inverting input.... it's marked this way consistently on the schematic. You have to feedback from the output to the inverting input (except for a Schmitt trigger). I verified this in the RCA data sheet for the CA3094 - pin 2 is inverting and pin 3 is non-inverting"






Frank Clarke - Frank has some nice modifications for existing circuits and nice new pedals. A very nice site!


GCS/Gus Smalley The following are circuits that are variants of existing circuits but with hand-picked substitution values/parts by Gus Smalley. Please try these...

Gus recommends an LF353 for the dual op amp. "The circled options are to make it
sound more like a Big Muff high and low end rolloffs". "When
you disconnect the feedback pot and leave just the 1n4148 diodes it goes
into what I call sick mode Think Edges U2 broken fuzz sound on POP tracks 1 and 2.
It also sounds very good in the loop of a lovetone meatball effect". "I use
100k audio pot on the output of effects because of the way the drive of
the IC and the pot interact with the 1st tube in a tube amp it has a
small tone effect".
My notes: I think this is an easy-to-build single IC chip distortion/fuzz. Experiment with the diodes (try LEDs, germanium diodes et...). Adjust the input and output caps to your liking.


Howie's Effects

Hemmo P. Another cool effects designer from our forum! His site is killer!

Iggy's Groove Guitar FX Webpage Lots of stuff here! The schematics have sound samples too!


Check out Pauley's Opamp Screamer. (Pauley's Effect Palace) Hand drawn layout (gty vbt)
Check out Bill Bergman's nice TS layout (TIFF file).
What is the Tubo Tube Screamer?
From Dai Hirokawa:
"TS9"(Normal) mode(for comparison): .047uF mylar w/two small signal Si diodes
"+" mode: 0.22uF polarized electrolytic w/four small signal Si diodes--two for the top of the waveform, two for bottom (these look the same as the ones used for the normal setting)
"Hot" mode: 1uF polarized electrolytic w/pair of LEDs(w/a 470k in parallel w/the LEDs)
"Turbo" mode: 2.2uF polarized electrolytic w/no diodes(seemed odd but it does look open)
-the 4.7k and 51k are unchanged for all modes


Jack Orman /AMZ

Order Jack's CD for all of his cool projects. Lots of the coolest pedals have been created with snippets and circuits of Jack Orman's work. Check out his creations!
Check out his forum.

Jay Doyle

Joe Davisson Joe is on a roll and is devising new pedals for us to try!

Joe Gagan - Watch for this guy!

John Greene

John Hollis - Cool Website too!


PCB Layout and more... on Guitars, Amps and Effects.



NG-04 Distortion Plus - (Guitar Tube Amps)









You can order boards for the above. Prices for boards are $10.00 each, including parts placement,and schematic.All anybody has to do is to send a self addressed, stamped envelope stating quantity to: Robert Shumway
                                                       41 Highmanor Drive
                                                       Henrietta, N.Y.14467
Send money order,and Robert will send out in mail the same day he receives orders. Apparently he has 1800 Dyna-Comp boards
Note: The input jack in the schematic is wired incorrectly. The connections to the input jack should be swapped between the 9V and ground. See the negative terminal of the battery should go to the middle connectore, not the tip as noted in the schematic. Thanks to Jack Orman for pointing this out.

Nobels Electronics



Prescription Electronic

Pro Co


R.G. Keen Check out his Guitar Effects FAQ! Oh man!

Rod Elliot Tons of interesting projects on his page.

Roger Mayer

I don't know.... A very fuzzy pedal. I guess it sounds OK. If you like FUZZ, then you might like this, however, I think the Lava Rim 2 is much better. Anyway, Jimi liked it right?



Sam Ash



Scott Swartz

Circuit1, Circuit2

Steve Daniels

Steve Giles

TC Electronics




Vintage Technology

Voodoo Labs

Gilles Caron, has a schematic, layout, and PCB files - bottom and top.


Wasi Raza

Wah Wah


You might want to check out "How to build a Superfuzz pedal"





Misc Distortion/Boosters

A very cool Japanese website with lots of cool projects on it. Thanks to Jack Orman for pointing this one out. Please check out the web site as there are more projects on there than I have listed here.

Speaker Simulators (misc)

Tube Distortions/Preamps



Cool Article Links!


Sites with Sound Samples/Settings

More Misc.

More fun/interesting places